Conventionally, coaxial cable signal distribution systems have been used to distribute television signals from a headend to end users. While interruptions to cable television (CATV) service are irritating and to be avoided, they are tolerated to a certain degree.
Coaxial cable signal distribution systems are currently being or soon will be used to transmit communications systems between end users. The tolerance for service disruptions in communications system is much lower than that for a CATV system. Accordingly, the CATV industry is taking more rigorous steps to avoid service disruptions in their coaxial cable signal distribution systems.
More specifically, coaxial cable signal distribution systems employ line extending amplifiers distributed throughout the system. The signal carried by the coaxial cable comprises a low frequency power portion and a high frequency information portion. The line extending amplifiers use the power portion to boost the signal strength of the information portion.
Power supplies are distributed throughout the coaxial cable signal distribution system to supply the power portion of the signal carried thereby. These power supplies are normally uninterruptible power supplies that obtain primary power from a utility power source and standby power from batteries. If the utility power source fails, a standby signal is generated using power supplied by the batteries. This level of back up has proven to be very effective in CATV signal distribution systems, but may not provide an adequate level of back up when the coaxial system is used to distribute communications signals.
A primary object of the present invention is thus to provide improved methods and systems for supplying power signals to coaxial cable signal distribution systems.